1. Field of the Invention
The present invention relates to land grid array (LGA) connectors, and particularly to an LGA connector for electrically connecting an electronic package such as an LGA central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), wherein the LGA connector movably engages a number of electrical contacts therein.
2. Description of the Prior Art
At present, LGA connectors are widely used to electrically connect LGA CPUs with PCBs. A typical LGA connector is disclosed in Taiwan Patent No. 444960. Referring to FIGS. 8 through 10, a conventional LGA connector 6 comprises an insulative housing 61, and a multiplicity of electrical contacts 62 received in the housing 61. The housing 61 is substantially rectangular, and defines a rectangular cavity 63 in a middle thereof for receiving an LGA CPU 8 therein. A portion of the housing 61 under the cavity 63 defines a multiplicity of passageways 631 therethrough. Each passageway 631 includes a pair of aligned slots 6310 in a middle thereof. The contacts 62 engage with the housing 61 in the corresponding slots 6310 of the passageways 631, respectively. Each contact 62 comprises an engaging portion 623, a contact portion 621 extending from an end of the engaging portion 623, and a solder portion 622 extending from another end of the engaging portion 623. A solder ball 624 is electrically mounted to the solder portion 622 by welding. The engaging portion 623 has a number of protrusions 6230. The protrusions 6230 of the contacts 62 interferentially engage the housing 61 at the corresponding slots 6310, such that the contacts 62 are secured in the housing 61. The contact portions 621 protrude out from a top surface 610 of the housing 61, and the solder balls 624 project down beyond a bottom surface 611 of the housing 61. Therefore, the contact portions 621 are liable to be accidentally damaged, particularly during shipping of the LGA connector 6.
In use, the LGA connector 6 is mounted to a PCB 9, with the solder balls 624 electrically connected with the PCB 9. The CPU 8 is mounted in the cavity 63 of the LGA connector 6. A force is applied to press the CPU 8 downwardly. Such force may be transmitted by another component such as a retention module (not shown). The contact portions 621 of the contacts 62 deform elastically such that the contact portions 621 firmly electrically connect with the CPU 8. The LGA connector 6 thus electrically connects the CPU 8 with the PCB 9. In this state, the solder balls 624 of the LGA connector 6 sustain the pressure applied from the retention module, and the solder balls 624 are liable to be damaged thereby. When any one or more of the solder balls 624 are damaged, the electrical connection between the CPU 8 and the PCB 9 is liable to be disrupted.
In view of the above, a new LGA connector that overcomes the above-mentioned disadvantages is desired.
Accordingly, an object of the present invention is to provide a land grid array (LGA) connector for electrically connecting an LGA central processing unit (CPU) with a printed circuit board (PCB), and particularly to an LGA connector which can be safely shipped.
Another object of the present invention is to provide a land grid array (LGA) connector for electrically connecting an LGA central processing unit (CPU) with a printed circuit board (PCB), and particularly to an LGA connector which has a housing configured to minimize the risk of solder balls being broken in use.
To achieve the above-mentioned objects, an LGA connector in accordance with a preferred embodiment of the present invention comprises an insulative housing, and a multiplicity of electrical contacts received in the housing. The housing is substantially rectangular, and has a plurality of stand-offs at a bottom surface thereof. Two aligned of the stand-offs at one side of the bottom surface are parallel to another of the stand-offs at an opposite side of the bottom surface. A rectangular cavity is defined in a middle of the housing for receiving an LGA CPU therein. A multiplicity of passageways is defined in a portion of the housing under the cavity. Each passageway includes a slot at an end thereof. The contacts engage with the housing in the slots respectively. Each contact comprises an engaging portion for engaging in the slot of one of passageways of the housing, a contact portion accommodated within the passageways, and a solder portion. A solder ball is mounted to the solder portion for electrically connecting with a PCB by welding. In use, a force is applied to press the CPU downwardly. The CPU presses the housing downwardly, and the engaging portion of each contact slides upwardly in the corresponding slot relative to the housing until the stand-offs make contact with a top surface of the PCB. The contact portion deforms elastically to firmly electrically connect with the CPU. The LGA connector thus reliably electrically connects the CPU with the PCB.